CVE-2026-71243

HIGH
Published Aug 5, 2026 Modified Aug 5, 2026 CWE-78

Description

The backmeup npm package assembles shell command strings by directly concatenating its option values (name, source, destination, filter) - e.g. cmd = "mkdir -p " + path.join(info.destination, info.name) + "; " - and executes the resulting string through a shell via ssh2-exec (locally via child_process, or remotely via SSH when an ssh handle is supplied), rather than using execFile/spawn with an argument array. The only processing applied is path.normalize()/path.join(), which do not neutralize shell metacharacters (;, |, &, $(), backticks, newline). Any application that passes attacker-influenced values into these options (e.g. a user-chosen backup name) is vulnerable to arbitrary OS command execution on the backup host, or on the remote SSH target when one is configured.

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CVSS v3.1 Score

8.8
HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Weakness Type (CWE)

CWE-78 OS Command Injection

References

Frequently Asked Questions

What is CVE-2026-71243? +
The backmeup npm package assembles shell command strings by directly concatenating its option values (name, source, destination, filter) - e.g. cmd = "mkdir -p " + path.join(info.destination, info.name) + "; " - and executes the resulting string through a shell via ssh2-exec (locally via child_process, or remotely via SSH when an ssh handle is supplied), rather than using execFile/spawn with an argument array. The only processing applied is path.normalize()/path.join(), which do not neutralize shell metacharacters (;, |, &, $(), backticks, newline). Any application that passes attacker-influenced values into these options (e.g. a user-chosen backup name) is vulnerable to arbitrary OS command execution on the backup host, or on the remote SSH target when one is configured. It has a CVSS v3.1 base score of 8.8 (HIGH).
How severe is CVE-2026-71243? +
CVE-2026-71243 has a CVSS v3.1 score of 8.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.
How do I check if I'm vulnerable to CVE-2026-71243? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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